Rail track NDT inspection is one of the ways how the current state of weld integrity can be assessed. Since half a century, radiographic examination of welds is a well-established technology that can provide a detailed report of the weld under inspection. Although several new inspection methods have emerged as an alternative method of inspection, the ability to examine the rail welds against flaws such as surface defects, sub-surface defects and internal defects buried in material leads a way forward for a customer to have greater confidence in radiographic approach. Rail track welds, switch blades and fish bolts can all be examined with the CIT/ Digital Radiography System. The technology is capable of examining components such as:
> Rail weld foot
> Middle web
> Rail head sections
The examination can be carried out within a short time span of 5 to 10 minutes per weld; the fastest inspection technique for weld and switch examination. Key defects like S transverse cracking can also be detected and corrective action can be in place to avoid major disasters.
The technology has been developed by using x-rays and CR Digital Radiography equipment. Previously used isotopes had presented problems of shipment. The x-ray radiography enables a more practical approach towards radiography. Digital Radiography, as it requires less dosage & exposure time becomes more cost effective and can move along the track to enhance productivity.
Railway regulators and safety assessment operators can benefit from the CIT/Centralized NDE Rail Weld Information Management System to manage the rail track infrastructure and carry out condition management.
Rail Inspection Data Report
An enterprise centralized NDE Digital Radiographic Rail Track Inspection Management System has been developed that keeps on-stream record of the entire infrastructure of the rail tracks. Risk Based Inspection (RBI) is used to analyze the critical sections of the tracks. This enables safety assessment operators to drill down the inspection raw data so as to establish key state of the item under examination. This is the fastest way to manage the predictive and corrective actions.
CIT/DR4200W Centralized NDE Digital Radiography Information Management System proves useful for managing information in a centralized manner.
A two year European funded CRAFT project has been completed in year 2004, which had developed various methods for inspection of rails. The inspection techniques covered were as follows:
> Phased Array
> Eddy Current
> Digital Radiography for welds and visual tracking
Due to the higher demand of speed of trains, the tracks are subjected to extensive predictable or unpredictable stresses in the material, which usually results in rail track failures. Worldwide, the statistics predict that high percentage of those failures resulted in accidents of large magnitude. Thus, continuous monitoring and predictive maintenance is the only way to safeguard the railways against such disasters. If risk analysis is carried out, one can examine the critical sections that are prone to disasters.
The project investigated detailed aspect of detection of flaws that can cause failures. For further details on project click here
Rail switch blades are critical sections of the track that require to be free of any defect and any extortions that the section undergo can influence the operational lifespan of the track. It is paramount that full historical information be retained and re-examined periodically to monitor the current status.
Digital Radiography is one method that can be used to inspect these blades and retain radiographic results from which defect propagation can be gauged. Although ultrasonic is currently used, an alternative is now available where digital radiography can be used to inspect complete section in less than 20 minutes of time (approx).
For further details on project click here
End customers, government authorities, rail regulators can contact CIT to discuss their applications to develop an intelligent information process control system to manage the inspection of their rail track assets and monitor the product life cycle of their operational rail track assets.